I checked out today of a 5 nights stay. I will not comment on how to get there from HKG, cws did this well. Just to point that from Mongkok station, taking the Place Langhan exit instead of E1 leads to more steps but less stairs as there are escalators everywhere but for one flight of stairs.

I was welcomed as a Gold by the charming agent, no upgrade as they were fairly full (i did check and they were selling only single low floor rooms), given a free drink voucher as well as free breakfast confirmed.
The room was good, standard size for HK but I did not felt squeezed in any way, good use of space.
Service was a bit weird: some very good staff and some really poor. The cleaner affected to my floor was very generous with giving me extra water bottle and was always checking with me if she could clean when she saw me in the corrridor. On the other hand I had a lady come in at 22:30 for a turn down service.
Same with breakfast staff; very variable. The buffet get boring fairly fast, but is OK enough.

The location was great for me as I wanted to concentrate on North Kowloon and the New Territories on that trip, and Mongkok offers lots of entertainment in the evening and place to eat.